[linux-sunxi] Re: [PATCH] nvmem: sunxi-sid: add support for A64/H5's SID controller

On Tue, Sep 19, 2017 at 04:23:14PM +0800, Icenowy Zheng wrote:

? 2017?9?19? GMT+08:00 ??4:20:19, Maxime Ripard [off-list ref] ??:

quoted

On Mon, Sep 18, 2017 at 11:42:04PM +0800, Icenowy Zheng wrote:

quoted

Allwinner A64/H5 SoCs come with a SID controller like the one in H3,

but

quoted

without the silicon bug that makes the initial value at 0x200 wrong,

so

quoted

the value at 0x200 can be directly read.

Add support for this kind of SID controller.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
---
 Documentation/devicetree/bindings/nvmem/allwinner,sunxi-sid.txt | 1

+

quoted

 drivers/nvmem/sunxi_sid.c                                       | 6

++++++

quoted

 2 files changed, 7 insertions(+)

diff --git

a/Documentation/devicetree/bindings/nvmem/allwinner,sunxi-sid.txt
b/Documentation/devicetree/bindings/nvmem/allwinner,sunxi-sid.txt

quoted

index ef06d061913c..6ea0836939ee 100644

--- a/Documentation/devicetree/bindings/nvmem/allwinner,sunxi-sid.txt
+++ b/Documentation/devicetree/bindings/nvmem/allwinner,sunxi-sid.txt

@@ -5,6 +5,7 @@ Required properties:
   "allwinner,sun4i-a10-sid"
   "allwinner,sun7i-a20-sid"
   "allwinner,sun8i-h3-sid"
+  "allwinner,sun50i-a64-sid"
 
 - reg: Should contain registers location and length
 

diff --git a/drivers/nvmem/sunxi_sid.c b/drivers/nvmem/sunxi_sid.c
index 0d6648be93b8..3c9fd4fb9207 100644
--- a/drivers/nvmem/sunxi_sid.c
+++ b/drivers/nvmem/sunxi_sid.c

@@ -199,10 +199,16 @@ static const struct sunxi_sid_cfg sun8i_h3_cfg

= {

quoted

 	.need_register_readout = true,
 };
 
+static const struct sunxi_sid_cfg sun50i_a64_cfg = {
+	.value_offset = 0x200,
+	.size = 0x100,
+};
+

How did you get those values?

In the BSP U-Boot headers.

This should be mentionned in your commit log then.

quoted

Also, it's reported that the SID can only be accessed in secure
mode, did you test it?

Yes, however the secure is broken again, and this only
happen if Secure Boot bit is burned.

Is broken again, meaning?

As far as I know, the only breakage we've had is on the A80 / A83T,
but we don't have anything like it on the A64, do we?

If it's really burned, we will have no clean way to access SID.

Well, in such a case we shouldn't access it either, so..

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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